Schedule definitions have several components to them, to permit flexibility:
Name Each schedule definition has a name. You can assign more than one schedule to a particular event, which can be useful in designing complex schedules.
Start time You can define a start time for the event, which is the time that it is first executed.
Range As an alternative to a start time, you can specify a range of times for which the event is active.
Recurrence Each schedule can have a recurrence. The event is triggered on a frequency that can be given in hours, minutes, or seconds, on a set of days that can be specified as days of the week or days of the month.